/****************************************************************************
 * apps/canutils/cansend/cansend.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) *
 *
 * cansend.c - send CAN-frames via CAN_RAW sockets
 *
 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Volkswagen nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * Alternatively, provided that this notice is retained in full, this
 * software may be distributed under the terms of the GNU General
 * Public License ("GPL") version 2, in which case the provisions of the
 * GPL apply INSTEAD OF those given above.
 *
 * The provided data structures and external interfaces from this code
 * are not restricted to be used by modules with a GPL compatible license.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * Send feedback to <linux-can@vger.kernel.org>
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <net/if.h>
#include <sys/ioctl.h>
#include <sys/socket.h>

#include <nuttx/can.h>

#include "lib.h"

static void print_usage_send(char *prg)
{
  fprintf(stderr, "%s - send CAN-frames via CAN_RAW sockets.\n", prg);
  fprintf(stderr, "\nUsage: %s <device> <can_frame>.\n", prg);
  fprintf(stderr, "\n<can_frame>:\n");
  fprintf(stderr,
          " <can_id>#{data}          ""for 'classic' CAN 2.0 data frames\n");
  fprintf(stderr,
          " <can_id>#R{len}          for 'classic' CAN 2.0 data frames\n");
  fprintf(stderr,
          " <can_id>##<flags>{data}  for CAN FD frames\n\n");
  fprintf(stderr, "<can_id>:\n"
          " 3 (SFF) or 8 (EFF) hex chars\n");
  fprintf(stderr, "{data}:\n"
          " 0..8 (0..64 CAN FD) ASCII hex-values "
          "(optionally separated by '.')\n");
  fprintf(stderr, "{len}:\n"
          " an optional 0..8 value "
          "as RTR frames can contain a valid dlc field\n");
  fprintf(stderr, "<flags>:\n"
          " a single ASCII Hex value (0 .. F) "
          "which defines canfd_frame.flags\n\n");
  fprintf(stderr, "Examples:\n");
  fprintf(stderr, "  5A1#11.2233.44556677.88 / 123#DEADBEEF / "
                  "5AA# / 123##1 / 213##311223344 /\n"
                  "  1F334455#1122334455667788 / 123#R / 00000123#R3\n\n");
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

int main(int argc, char **argv)
{
  /* can raw socket */

  int s;
  int required_mtu;
  int mtu;
  int enable_canfd = 1;
  struct sockaddr_can addr;
  struct canfd_frame frame;
  struct ifreq ifr;

  /* check command line options */

  if (argc != 3)
    {
      print_usage_send(argv[0]);
      return 1;
    }

  /* parse CAN frame */

  required_mtu = parse_canframe(argv[2], &frame);
  if (!required_mtu)
    {
      fprintf(stderr, "\nWrong CAN-frame format!\n\n");
      print_usage_send(argv[0]);
      return 1;
    }

  /* open socket */

  if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
    {
      perror("socket");
      return 1;
    }

  strlcpy(ifr.ifr_name, argv[1], IFNAMSIZ);
  ifr.ifr_ifindex = if_nametoindex(ifr.ifr_name);
  if (!ifr.ifr_ifindex)
    {
      perror("if_nametoindex");
      return 1;
    }

  memset(&addr, 0, sizeof(addr));
  addr.can_family = AF_CAN;
  addr.can_ifindex = ifr.ifr_ifindex;

  if (required_mtu > (int)CAN_MTU)
    {
      /* check if the frame fits into the CAN netdevice */

      if (ioctl(s, SIOCGIFMTU, &ifr) < 0)
        {
          perror("SIOCGIFMTU");
          return 1;
        }

      mtu = ifr.ifr_mtu;

      if (mtu != CANFD_MTU)
        {
          printf("CAN interface is not CAN FD capable - sorry.\n");
          return 1;
        }

      /* interface is ok - try to switch the socket into CAN FD mode */

      if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FD_FRAMES,
                     &enable_canfd, sizeof(enable_canfd)))
        {
          printf("error when enabling CAN FD support\n");
          return 1;
        }

      /* ensure discrete CAN FD length values 0..8, 12, 16, 20, 24, 32, 64 */

      frame.len = can_dlc2len(can_len2dlc(frame.len));
    }

  /* disable default receive filter on this RAW socket
   * This is obsolete as we do not read from the socket at all, but for
   * this reason we can remove the receive list in the Kernel to save a
   * little (really a very little!) CPU usage.
   */

  setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);

  if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
    {
      perror("bind");
      return 1;
    }

  /* send frame */

  if (write(s, &frame, required_mtu) != required_mtu)
    {
      perror("write");
      return 1;
    }

  close(s);

  return 0;
}
